Darrel--

There aren't any real hard design requirements, though some regulatory groups have electrical spacing
requirements.

As a start, use the IPC-D-275/IPC-2221, electrical spacing requirements from the "A" columns.

Most electronic packaging has a minimum electrical spacing requirement depending on worst case analysis.

Don't forget to allow for the printed board, cover of "chassis plate" to "flex" due to mechanical shock or
vibration.

Ralph

Darrel Therriault wrote:

> Designers,
>
> We have a midplane attached to a metal chassis.  There are some vias that
> appear to be very close to the chassis and I was wondering what the
> guideline is for spacing from any via/etch/signal to chassis might be.
> While I am busy looking through the IPC design rules, I thought I'd throw
> it out on Technet to see what other opinions and guidelines might be shared.
>
> Thanks in advance.....DT
>
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--
Ralph Hersey

Ralph Hersey & Associates
3885 Mills Way
Livermore, CA 94550-3319
PHN/FAX: 925.454.9805
e-mail: [log in to unmask]

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